The present invention relates to a method of and an arrangement for measuring a size of highly throughgoing openings produced energy radiation, for example laser radiation in workpieces during a working process.
More particularly it relates to a method of measurement of the above mentioned type in which each opening is produced by several successive energy pulses with focal points offset relative to an axis of the opening.
German document DE-OS 1,790,128 discloses a method and an arrangement for drilling workpieces, especially watch stones by means of a laser radiation, in which each opening is produced by several successive pulses with focal points offset transversely to the opening axis. The desired opening diameter can be produced by energy pulses acting annularly around the axis of the opening to be produced, and the eccentricity of the focal points of individual pulses relative the axis of the opening to be produced is correspondingly adjusted. For this purpose preferably an optical system with movable optical means for displacing the focal point transversely to the optical axis is utilized. The number of power of the pulses must be empirically determined, depending on the diameter of the borehole, the thickness of the workpiece, the material properties and other parameters.